Wiring harnesses conventionally connect each individual input to one respective output. This can limit full use of the incoming signal. Conventionally an amplifier has its own power source and an audio source has its own power source, creating expense and wiring complexity. Wiring harnesses for audio systems generally vary according to the number of channels sent by the audio source and used by the amplifier. Amplifiers are commercially available with two, four, five (also called four-point-one), and six channels.